When there's a plane crash, U.S. airlines have to follow strict rules for taking care of families, down to the kind of hotel they stay at. But that doesn't help the families of the passengers on MH370.

The mystery over what happened to Malaysia Airlines Flight 370 is taking a particularly hard toll on the relatives of the 229 passengers; and some of the family members are now threatening a hunger strike to force the Malaysian authorities to be more forthcoming about what they know.

But what about the role of the airline? It’s the carrier, after all, that has the best information about who was on the plane, whom to contact in an emergency, and other critical details that are vital in the first hours and days following an event.

"Families are clearly the most important audience in a disaster of this kind," says Jerry Hendin, who wrote the industry’s first crisis communications manual while at Boeing, and now consults for airlines and other clients. "For airlines, the most important part is the communications with the families," he says.

But clear guidelines on how to proceed—and the role of an airline’s far-flung staff—have often been lacking. Widespread outrage over the treatment of relatives in some major accident investigations prompted Congress, in 1996, to pass a law mandating a series of reforms; the National Transportation Safety Board subsequently produced a comprehensive plan—the 75-page document, most recently revised in 2008, is available on the NTSB site—which spells out such details as how fast the airline must set up a special toll-free number for families, and what transportation they must offer to those traveling to the accident. The message is unequivocal: "The air carrier has a fundamental responsibility to the victims and their families affected by an aviation disaster," it says. The document also clarifies that the term ‘family members’ can refer to any person who has a relationship with someone involved in the accident. And it gets into matters such as the quality of hotel accommodations offered to relatives ("Consideration should be given to a facility that has multiple meeting rooms, a large ballroom, up-to-date information technology infrastructure, and food services") and recordings for those waiting on hold (carriers should "modify normal on hold messages to eliminate music, sales information and similar non-accident related messages").

While laudable in its intent, the NTSB’s plan only affects U.S.-based airlines or accidents that take place in the U.S., such as the crash of Asiana Flight 214 last summer in San Francisco. That airline was fined $500,000 recently by the Department of Transportation for taking too long to notify victims—three of the 291 passengers were killed, and nearly 200 had some injuries. It was believed to be the first such penalty against an airline for failing to live up to the NTSB guidelines.

According to Hendin, most major international airlines conduct regular crisis training for their employees who have regular contact with the public. Among other things, airlines train their station managers and assistant managers throughout their networks on what would happen in the event of an accident – especially one that’s far from the carrier’s headquarters.

In the training sessions, Hendin says the message to employees is "all crises are predictable and they can plan for it." Except in the case of Malaysia MH370, where there is virtually no precedent for what has happened.